CN113906671A - Doherty amplifier - Google Patents
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- CN113906671A CN113906671A CN201980097069.1A CN201980097069A CN113906671A CN 113906671 A CN113906671 A CN 113906671A CN 201980097069 A CN201980097069 A CN 201980097069A CN 113906671 A CN113906671 A CN 113906671A
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
- H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
- H03F1/0288—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter, e.g. Doherty amplifiers
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/56—Modifications of input or output impedances, not otherwise provided for
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
- H03F3/21—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only
- H03F3/211—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only using a combination of several amplifiers
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/60—Amplifiers in which coupling networks have distributed constants, e.g. with waveguide resonators
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Abstract
A Doherty amplifier (100) is provided with: amplifiers (8, 9) comprising a main amplifier (8) and an auxiliary amplifier (9); output circuits (10, 13) for back-off amplification, which include a1 st output circuit (10) having a1 st electrical length (theta 1) provided between the main amplifier (8) and an output combining unit (18) of the amplifiers (8, 9), and a2 nd output circuit (13) having a2 nd electrical length (theta 2) provided between the auxiliary amplifier (9) and the output combining unit (18); and a frequency characteristic compensation circuit (15) for widening the bandwidth, which is provided in parallel with the 1 st output circuit (10) electrically and compensates the frequency characteristic of the impedance in the output circuits (10, 13).
Description
Technical Field
The present invention relates to a Doherty amplifier (Doherty amplifier).
Background
In recent years, the PAPR (Peak to Average Power Ratio) of a modulated signal for communication has been increased due to an increase in traffic. In order to cope with the expansion of PAPR, an amplifier for a communication device is required to have improved efficiency in an operating state (hereinafter, referred to as "back-off operating state") based on output power lower than saturated output power.
In a normal amplifier, the efficiency in the back-off operation state is lower than the efficiency in the operation state based on the saturation output power (hereinafter, referred to as the "saturation operation state"). More specifically, as the output power decreases, the efficiency gradually decreases. In contrast, by using the doherty amplifier, the efficiency in the back-off operation state can be improved.
That is, the doherty amplifier has a main amplifier, a so-called "carrier amplifier". Furthermore, the doherty amplifier has an auxiliary amplifier, the so-called "peak amplifier". When the output power requested by the doherty amplifier (hereinafter referred to as "requested output power") is equal to or greater than a predetermined value, the carrier amplifier is set to an on state, and the peak amplifier is set to an on state. On the other hand, when the requested output power is less than the prescribed value, the carrier amplifier is set to the on state, and the peak amplifier is set to the off state.
Thus, in the fallback operation state based on the output power corresponding to the predetermined value, the same efficiency as that in the saturation operation state is achieved. More specifically, in the back-off operation state based on an output power that is about 6 decibels (hereinafter, referred to as "dB") lower than the saturation output power, the same efficiency as that in the saturation operation state is achieved. As a result, the PAPR of about 6dB can be handled.
Hereinafter, the difference between the saturated output power and the output power that achieves the same efficiency in the back-off operation state as that in the saturated operation state is referred to as a "back-off amount". That is, the doherty amplifier can cope with the PAPR corresponding to the back-off amount. Therefore, patent document 1 discloses a technique for making the back-off of the doherty amplifier larger than 6 dB.
That is, a phase line (21) is provided between the carrier amplifier (3) and the output combining point (13) (see fig. 1 and the like of patent document 1). Further, a phase line (23) is provided between the peak amplifier (7) and the output combining point (13) (see fig. 1 and the like of patent document 1). The electrical length (theta) of the phase line (21) is set here1) Is set to a value based on a predetermined mathematical expression (see expression (1) of patent document 1). Furthermore, the electrical length (theta) of the phase line (23)2) Is set to a value based on another predetermined mathematical expression (see expression (2) of patent document 1). This realizes a back-off larger than 6dB (see fig. 4 and the like of patent document 1).
Documents of the prior art
Patent document
Patent document 1: international publication No. 2007/015462
Disclosure of Invention
Problems to be solved by the invention
As described later with reference to fig. 1 to 7, in the conventional doherty amplifier, particularly when the auxiliary amplifier is set to the off state, the impedance on the output side with respect to the main amplifier greatly varies depending on the frequency. This impedance variation has a problem that the operable frequency band (hereinafter referred to as "operating frequency band") is narrow.
The present invention has been made to solve the above-described problems, and an object of the present invention is to simultaneously expand a back-off amount and amplify an operating frequency band (hereinafter referred to as "widening band") in a doherty amplifier.
Means for solving the problems
The doherty amplifier of the present invention comprises: an amplifier comprising a main amplifier and an auxiliary amplifier; an output circuit for back-off amplification, which includes a1 st output circuit having a1 st electrical length and provided between the main amplifier and the output combining section of the amplifier, and a2 nd output circuit having a2 nd electrical length and provided between the auxiliary amplifier and the output combining section; and a frequency characteristic compensation circuit for widening a band, which is provided electrically in parallel with the 1 st output circuit and compensates for a frequency characteristic of impedance in the output circuit.
Effects of the invention
According to the present invention, since the configuration is as described above, it is possible to simultaneously realize the expansion of the back-off amount and the widening of the bandwidth.
Drawings
Fig. 1 is a circuit diagram showing main parts of a doherty amplifier of embodiment 1.
Fig. 2 is a circuit diagram showing main parts of a comparative doherty amplifier.
Fig. 3 is an explanatory diagram showing impedances when the auxiliary amplifier in the doherty amplifier of embodiment 1 is set to an off state.
Fig. 4 is an explanatory diagram showing impedances when the auxiliary amplifier in the comparative doherty amplifier is set to an off state.
Fig. 5 is an explanatory diagram showing impedance conversion when the auxiliary amplifier in the doherty amplifier of embodiment 1 is set to the off state.
Fig. 6 is an explanatory diagram showing impedance conversion when the auxiliary amplifier in the comparative doherty amplifier is set to the off state.
Fig. 7 is a characteristic diagram showing the reflection amount with respect to frequency.
Fig. 8 is an explanatory diagram showing the impedance when the auxiliary amplifier in the doherty amplifier of embodiment 1 is set to the on state.
Fig. 9 is a circuit diagram showing the main parts of the doherty amplifier of embodiment 2.
Fig. 10 is a circuit diagram showing the main parts of the doherty amplifier of embodiment 3.
Fig. 11 is a circuit diagram showing the main parts of the doherty amplifier of embodiment 4.
Fig. 12 is a circuit diagram showing the main parts of the doherty amplifier of embodiment 5.
Detailed Description
Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the drawings.
Fig. 1 is a circuit diagram showing main parts of a doherty amplifier of embodiment 1. A doherty amplifier of embodiment 1 will be described with reference to fig. 1.
Hereinafter, unless otherwise specified, the value of the electrical length is assumed to be a value at a predetermined frequency (hereinafter, referred to as "reference frequency") f _ ref. The reference frequency f _ ref is set to, for example, the same value as the center frequency f _ center in a used frequency band (hereinafter referred to as a "used frequency band").
In the drawing, 1 is an input terminal. The input terminal 1 is electrically connected to a signal source (not shown). The input terminal 1 receives a signal input to the doherty amplifier 100. An input matching circuit 2 ("IMN" in the drawing) is provided between the input terminal 1 and the distributor 3. The input matching circuit 2 is a circuit for obtaining impedance matching between the input terminal 1 and the distributor 3. The input matching circuit 2 is composed of, for example, a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines.
The distributor 3 distributes the output signal of the input matching circuit 2 to 2 paths P1, P2. The distributor 3 outputs the distributed signal. One path (hereinafter, sometimes referred to as "1 st path") P1 of the 2 paths P1, P2 is a path including the main amplifier 8. The other path (hereinafter, sometimes referred to as "2 nd path") P2 of the 2 paths P1 and P2 is a path including the auxiliary amplifier 9.
The divider 3 is formed of, for example, a wilkinson divider or a hybrid circuit. Each circuit in the hybrid circuit is composed of, for example, a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines.
An input matching circuit (hereinafter, referred to as "1 st input matching circuit") 4 is provided between the distributor 3 and the main amplifier 8. The 1 st input matching circuit 4 is a circuit for matching the inputs of the main amplifier 8. The 1 st input matching circuit 4 is composed of, for example, a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines.
A phase correction circuit 5 is provided between the distributor 3 and the auxiliary amplifier 9. The phase correction circuit 5 is a circuit in which the electrical length of the 2 nd path P2 is made equal to the electrical length of the 1 st path P1. The phase correction circuit 5 is constituted by a transmission line 6, for example. The transmission line 6 has the same electrical length as the difference in electrical length between the paths P1, P2.
An input matching circuit (hereinafter, referred to as "2 nd input matching circuit") 7 is provided between the distributor 3 and the auxiliary amplifier 9. More specifically, the 2 nd input matching circuit 7 is provided between the phase correction circuit 5 and the auxiliary amplifier 9. The 2 nd input matching circuit 7 is a circuit for matching the inputs to the auxiliary amplifier 9. The 2 nd input matching circuit 7 is composed of, for example, a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines.
The main amplifier 8 amplifies the output signal of the 1 st input matching circuit 4. The main amplifier 8 outputs the amplified signal. The main amplifier 8 is formed of a transistor. Specifically, the main amplifier 8 is constituted by, for example, a FET (Field Effect Transistor), an HBT (Heterojunction Bipolar Transistor), or an HEMT (High Electron Mobility Transistor). The gate bias of the main amplifier 8 is set to a value corresponding to so-called "class a", a value corresponding to so-called "class B", or a value between class a and class B.
The auxiliary amplifier 9 amplifies the output signal of the 2 nd input matching circuit 7. The auxiliary amplifier 9 outputs the amplified signal. The auxiliary amplifier 9 is formed of a transistor. Specifically, the auxiliary amplifier 9 is composed of, for example, an FET, HBT, or HEMT. The gate bias of the auxiliary amplifier 9 is set to a value corresponding to so-called "C-stage".
Hereinafter, the main amplifier 8 and the auxiliary amplifier 9 may be collectively referred to simply as "amplifier". In the amplifiers 8, 9, electrical characteristics (e.g., output resistance and output amplitude) of the outputs with respect to the bias amount are the same as each other. Therefore, assuming that the bias amounts of the amplifiers 8, 9 are set to the same values as each other, the electrical characteristics of the output of the main amplifier 8 are the same as the electrical characteristics of the output of the auxiliary amplifier 9. In this case, the saturated output power of the main amplifier 8 is the same as that of the auxiliary amplifier 9.
In the drawing, 18 denotes a portion (hereinafter referred to as an "output combining portion") that combines the outputs of the amplifiers 8 and 9. The 1 st output circuit 10 is provided between the main amplifier 8 and the output combining unit 18. The 1 st output circuit 10 is constituted by, for example, 2 transmission lines 11 and 12. One transmission line (hereinafter, referred to as "1 st transmission line") 11 of the 2 transmission lines 11, 12 indicates an electrical length of 90 degrees or substantially 90 degrees. The other transmission line (hereinafter, referred to as "2 nd transmission line") 12 of the 2 transmission lines 11, 12 has an electrical length of less than 90 degrees.
Further, a2 nd output circuit 13 is provided between the auxiliary amplifier 9 and the output combining section 18. The 2 nd output circuit 13 is constituted by a transmission line (hereinafter, referred to as "3 rd transmission line") 14, for example. The 3 rd transmission line 14 has an electrical length of less than 90 degrees. Hereinafter, the 1 st output circuit 10 and the 2 nd output circuit 13 may be collectively referred to simply as "output circuits".
Here, the electrical length (hereinafter referred to as "1 st electrical length") θ 1 of the 1 st output circuit 10, that is, the total electrical length of the 1 st transmission line 11 and the 2 nd transmission line 12 is set to a value based on the following expression (1). The characteristic impedance of the 1 st output circuit 10 is set to the same value as the optimum load impedance Ropt1 in the saturation operating state of the main amplifier 8.
The electrical length of the 2 nd output circuit 13 (hereinafter referred to as "2 nd electrical length") θ 2, that is, the electrical length of the 3 rd transmission line 14 is set to a value based on the following expression (2). The characteristic impedance of the 2 nd output circuit 13 is set to the same value as the optimum load impedance Ropt2 in the saturation operation state of the auxiliary amplifier 9. Here, Ropt2 is set to the same value as Ropt 1. For example, Ropt 1-Ropt and Ropt 2-Ropt.
γ in the above equations (1) and (2) is a value corresponding to a back-off amount (hereinafter referred to as "requested back-off amount") OBO requested by the doherty amplifier 100. More specifically, γ is a value based on the following formula (3).
OBO[dB]＝10log10(γ) (3)
That is, the total electrical length of the 2 nd transmission line 12 and the 3 rd transmission line 14 is set to 90 degrees or substantially 90 degrees. Therefore, the total electrical length of the 1 st transmission line 11, the 2 nd transmission line 12, and the 3 rd transmission line 14 is set to 180 degrees or substantially 180 degrees. In other words, the total electrical length of the 1 st output circuit 10 and the 2 nd output circuit 13 is set to 180 degrees or substantially 180 degrees.
In addition, the parasitic component of the main amplifier 8 is compensated by an inductor (not shown). Alternatively, the parasitic component of the main amplifier 8 is taken into the 1 st output circuit 10 in the circuit. Therefore, the 1 st output circuit 10 is directly connected to the output portion of the main amplifier 8 from the viewpoint of electrical length. In addition, the parasitic component of the auxiliary amplifier 9 is compensated by other inductors (not shown). Alternatively, the parasitic component of the auxiliary amplifier 9 is taken into the 2 nd output circuit 13 in the circuit. Therefore, the 2 nd output circuit 13 is directly connected to the output portion of the auxiliary amplifier 9 in terms of electrical length.
Hereinafter, a characteristic indicating impedance with respect to frequency is referred to as "frequency characteristic". The doherty amplifier 100 has a frequency characteristic compensating circuit 15. The frequency characteristic compensation circuit 15 is a circuit that compensates for the frequency characteristic in the output circuits 10 and 13 when the auxiliary amplifier 9 is set to the off state. The compensation of the frequency characteristic by the frequency characteristic compensation circuit 15 will be described later with reference to fig. 1 to 7.
The frequency characteristic compensation circuit 15 is electrically connected in parallel to the 1 st output circuit 10. The frequency characteristic compensation circuit 15 is constituted by, for example, an open stub 16 having an electrical length of 180 degrees or substantially 180 degrees. In the drawing, reference numeral 17 denotes a portion (hereinafter, referred to as a "connection portion") connecting the 1 st transmission line 11, the 2 nd transmission line 12, and the open stub 16.
In the paths P1 and P2, no so-called "isolation" is performed at a portion P3 on the output side of the amplifiers 8 and 9 (hereinafter referred to as a "partial path"). As shown in fig. 1, the partial path P3 is a portion of the paths P1 and P2 including the 1 st output circuit 10, the 2 nd output circuit 13, and the output combining unit 18.
An output matching circuit 19 ("OMN" in the drawing) is provided between the output combining section 18 and the output terminal 20. The output matching circuit 19 is a circuit for obtaining impedance matching between the output combining unit 18 and the output terminal 20. The output matching circuit 19 is composed of, for example, a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines. The output terminal 20 is electrically connected to a load 21.
The input terminal 1, the input matching circuit 2, the divider 3, the 1 st input matching circuit 4, the phase correction circuit 5, the 2 nd input matching circuit 7, the main amplifier 8, the auxiliary amplifier 9, the 1 st output circuit 10, the 2 nd output circuit 13, the frequency characteristic compensation circuit 15, the output matching circuit 19, and the output terminal 20 constitute the main parts of the doherty amplifier 100.
Next, the operation of the doherty amplifier 100 will be described with reference to fig. 1 to 7, centering on the impedance transition when the auxiliary amplifier 9 is set to the off state. Meanwhile, the effect of the doherty amplifier 100 will be explained. Further, let Ropt1 be Rop and Ropt2 be Ropt.
Fig. 2 shows a doherty amplifier 100' for comparison with the doherty amplifier 100. As shown in fig. 2, the doherty amplifier 100' does not have the frequency characteristic compensating circuit 15. That is, the doherty amplifier 100' corresponds to a conventional doherty amplifier described in patent document 1 and the like.
Fig. 3 shows the impedance in the doherty amplifier 100 when the auxiliary amplifier 9 is set to the off state. In the drawing, Γ 1 represents the impedance of the output terminal 20 side as viewed from the output combining unit 18. Γ 2 represents the impedance of the 2 nd transmission line 12 as viewed from the output terminal 20 side. Γ 3 represents the impedance of the output terminal 20 side as viewed from the connection portion 17. Γ 4 represents the impedance of the 1 st transmission line 11 as viewed from the output terminal 20 side. Γ 5 represents an impedance of the output terminal 20 side as viewed from the output unit of the main amplifier 8.
Fig. 4 shows the impedance in the doherty amplifier 100' when the auxiliary amplifier 9 is set to the off state. In the drawing, Γ 1' represents the impedance of the output terminal 20 side as viewed from the output combining section 18. Γ 2' represents the impedance of the 2 nd transmission line 12 as viewed from the output terminal 20 side. Γ 4' represents the impedance of the 1 st transmission line 11 as viewed from the output terminal 20 side. Γ 5' represents the impedance of the output terminal 20 side as viewed from the output portion of the main amplifier 8.
Fig. 5 is a smith chart depicting Γ 2, Γ 4, and Γ 5. In the figure, arrow a1 shows the impedance transformation from Γ 2 to Γ 4. Further, arrow a2 shows the impedance transformation from Γ 4 to Γ 5. As shown in fig. 5, Γ 2, Γ 4, and Γ 5 vary with frequency.
Fig. 6 is a smith chart depicting Γ 2 ', Γ 4 ', and Γ 5 '. In the figure, arrow a1 ' shows the impedance transformation from Γ 2 ' to Γ 4 '. Furthermore, arrow a2 ' shows the impedance transformation from Γ 4 ' to Γ 5 '. As shown in fig. 6, Γ 2 ', Γ 4 ', Γ 5 ' fluctuate depending on the frequency.
Hereinafter, a frequency domain f _ high higher than the center frequency f _ center of the used frequency band, that is, a frequency domain f _ high higher than the reference frequency f _ ref is referred to as a "high frequency domain". The frequency domain f _ low lower than the center frequency f _ center of the used frequency band, that is, the frequency domain f _ low lower than the reference frequency f _ ref is referred to as a "low frequency domain".
When the required output power to the doherty amplifier 100 is equal to or higher than a predetermined value, the main amplifier 8 is set to an on state, and the auxiliary amplifier 9 is set to an on state. On the other hand, when the requested output power to the doherty amplifier 100 is smaller than a prescribed value, the main amplifier 8 is set to an on state and the auxiliary amplifier 9 is set to an off state. The same is true in the doherty amplifier 100'.
When the auxiliary amplifier 9 is set to the off state, the impedance on the auxiliary amplifier 9 side as viewed from the output portion of the auxiliary amplifier 9 becomes infinite ("Open" in the drawing). Therefore, when the auxiliary amplifier 9 is set to the off state, the 2 nd output circuit 13 functions as an open stub. Here, since the electrical length of the 2 nd output circuit 13 is less than 90 degrees, the 2 nd output circuit 13 functions as a capacitive load when the auxiliary amplifier 9 is set to the off state.
On the other hand, Γ 2 in the doherty amplifier 100 is a capacitive impedance (see fig. 5). Γ 2 'in the doherty amplifier 100' is also a capacitive impedance (see fig. 6). This is because the 2 nd output circuit 13 functions as a capacitive load.
In the doherty amplifier 100, since the 2 nd transmission line 12 is provided, Γ 2 is converted to Γ 3. Further, since the frequency characteristic compensation circuit 15 is provided, Γ 3 is converted to Γ 4. That is, since the 2 nd transmission line 12 and the frequency characteristic compensation circuit 15 are provided, Γ 2 is converted to Γ 4 (see fig. 5).
On the other hand, in the doherty amplifier 100 ', since the 2 nd transmission line 12 is provided, Γ 2 ' is converted to Γ 4 ' (see fig. 6). Γ 4' is an inductive impedance in the high frequency domain f _ high and a capacitive impedance in the low frequency domain f _ low (see fig. 6).
That is, the 2 nd transmission line 12 in the doherty amplifier 100 functions to bring Γ 4 closer to the solid axis Re than Γ 2 by bringing Γ 3 closer to the solid axis Re than Γ 2. In other words, the 2 nd transmission line 12 in the doherty amplifier 100 functions to return the impedance (Γ 1 → Γ 2) distant from the real axis Re to the vicinity of the real axis Re through the 2 nd output circuit 13 (Γ 2 → Γ 3).
Further, the 2 nd transmission line 12 in the doherty amplifier 100 ' functions to bring Γ 4 ' closer to the real axis Re than Γ 2 '. In other words, the 2 nd transmission line 12 in the doherty amplifier 100 ' functions to return the impedance (Γ 1 ' → Γ 2 ') distant from the real axis Re to the vicinity of the real axis Re through the 2 nd output circuit 13 (Γ 2 ' → Γ 4 ').
In the doherty amplifier 100, since the 1 st transmission line 11 is provided, Γ 4 is converted to Γ 5 (see fig. 5). Further, in the doherty amplifier 100 ', since the 1 st transmission line 11 is provided, Γ 4 ' is converted to Γ 5 ' (see fig. 6).
Here, as shown in fig. 5 and 6, the variation of Γ 5' with respect to frequency is larger than the variation of Γ 5 with respect to frequency. Therefore, the operating band of the doherty amplifier 100' is narrower than that of the doherty amplifier 100.
In other words, the variation of Γ 5 with respect to frequency is smaller than the variation of Γ 5' with respect to frequency. Therefore, the operating frequency band of the doherty amplifier 100 is wider than that of the doherty amplifier 100'. This is because the frequency characteristic compensation circuit 15 is provided to compensate for the frequency characteristic in the output circuits 10 and 13.
That is, regarding the frequency characteristics in the 1 st transmission line 11, the impedance is inductive in the high frequency domain f _ high, and the impedance is capacitive in the low frequency domain f _ low. In addition, regarding the frequency characteristics in a circuit (hereinafter, referred to as a "synthesis circuit") including the 2 nd transmission line 12 and the 3 rd transmission line 14, the impedance is inductive in the high frequency range f _ high and the impedance is capacitive in the low frequency range f _ low.
Therefore, in the high frequency band f _ high, when the output terminal 20 side is viewed from the output part of the main amplifier 8, the inductive impedance of the 1 st transmission line 11 and the inductive impedance of the combining circuit are in a mutually intensified relationship. On the other hand, in the low frequency band f _ low, when the output terminal 20 side is viewed from the output portion of the main amplifier 8, the capacitive impedance of the 1 st transmission line 11 and the capacitive impedance of the combining circuit have a mutually enhanced relationship. Therefore, Γ 5 'in the doherty amplifier 100' greatly varies depending on the frequency.
In contrast, regarding the frequency characteristics in the frequency characteristic compensation circuit 15, the impedance is capacitive in the high frequency domain f _ high, the impedance is infinite in the center frequency f _ center, and the impedance is inductive in the low frequency domain f _ low.
Therefore, in the high frequency band f _ high, the capacitive impedance of the frequency characteristic compensation circuit 15 functions to cancel the inductive impedance of the output circuits 10 and 13 when the output terminal 20 side is viewed from the output part of the main amplifier 8. On the other hand, in the low frequency range f _ low, when the output terminal 20 side is viewed from the output part of the main amplifier 8, the inductive impedance of the frequency characteristic compensation circuit 15 functions to cancel the capacitive impedance of the output circuits 10 and 13. Therefore, the variation of Γ 5 with respect to frequency is smaller than the variation of Γ 5' with respect to frequency.
In this way, the doherty amplifier 100 can increase the back-off amount by providing the output circuits 10 and 13, as in the doherty amplifier 100'. In addition, the doherty amplifier 100 can expand an operation band compared to the doherty amplifier 100' by providing the frequency characteristic compensation circuit 15.
Fig. 7 is a characteristic diagram showing the amount of reflection of the output power of the main amplifier 8 with respect to the frequency. In the drawing, a characteristic line I represents a reflection amount when the auxiliary amplifier 9 in the doherty amplifier 100 is set to the off state. On the other hand, the characteristic line II represents the reflection amount when the auxiliary amplifier 9 in the doherty amplifier 100' is set to the off state.
As shown in fig. 7, by using the doherty amplifier 100, the amount of reflection can be reduced in a larger frequency range than the case of using the doherty amplifier 100'. Therefore, by using the doherty amplifier 100, the operating band can be enlarged as compared with the case of using the doherty amplifier 100'.
Next, referring to fig. 8, the impedance of the doherty amplifier 100 when the auxiliary amplifier 9 is set to the on state will be described. More specifically, the impedance in the saturation operation state will be described.
In the drawing, Γ 5 represents an impedance viewed from the output portion of the main amplifier 8 on the output terminal 20 side. Γ 6 represents an impedance of the auxiliary amplifier 9 as viewed from the output portion on the output terminal 20 side.
In this case, Γ 6 is the same impedance as Ropt. Here, as described above, Ropt2 is Ropt. Therefore, Γ 6 is in a state of matching the optimum load impedance Ropt2 of the auxiliary amplifier 9.
Next, a modified example of the doherty amplifier 100 will be described.
The phase correction circuit 5 is not limited to the transmission line 6. For example, the phase correction circuit 5 is composed of a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines.
The 1 st output circuit 10 is not limited to the 1 st transmission line 11 and the 2 nd transmission line 12. For example, the 1 st output circuit 10 may be configured by 1 transmission line (not shown) having an electrical length of 90 degrees or more.
The 2 nd output circuit 13 is not limited to the 3 rd transmission line 14. For example, the 2 nd output circuit 13 may be configured by a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines.
The frequency characteristic compensation circuit 15 is not limited to the open stub 16. For example, the frequency characteristic compensation circuit 15 may be configured by a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a transmission line having an electrical length of 90 degrees or substantially 90 degrees. That is, the frequency characteristic compensation circuit 15 may be constituted by a stub.
As described above, the doherty amplifier 100 has: amplifiers 8, 9, which include a main amplifier 8 and an auxiliary amplifier 9; output circuits 10, 13 for back-off amplification including a1 st output circuit 10 provided between the main amplifier 8 and an output combining section 18 of the amplifiers 8, 9 and having a1 st electrical length θ 1, and a2 nd output circuit 13 provided between the auxiliary amplifier 9 and the output combining section 18 and having a2 nd electrical length θ 2; and a frequency characteristic compensation circuit 15 for widening a band, which is provided electrically in parallel with the 1 st output circuit 10 and compensates for a frequency characteristic of impedance in the output circuits 10 and 13. This makes it possible to simultaneously increase the back-off and widen the bandwidth.
When the auxiliary amplifier 9 is set to the off state, the 2 nd output circuit 13 functions as an open stub, and thus the 2 nd output circuit 13 functions as a capacitive load. This can increase the back-off amount.
Further, in a high frequency region f _ high with respect to the reference frequency f _ ref, the capacitive impedance of the frequency characteristic compensation circuit 15 cancels the inductive impedance of the output circuits 10, 13, and in a low frequency region f _ low with respect to the reference frequency f _ ref, the inductive impedance of the frequency characteristic compensation circuit 15 cancels the capacitive impedance of the output circuits 10, 13. This makes it possible to realize a wider band.
The 1 st electrical length θ 1 is set based on the equation using the value γ corresponding to the requested back-off OBO
Value of (2 nd electrical length)The degree θ 2 is set based on the equation using the value γ corresponding to the requested back-off OBO
The value of (c). That is, the 1 st electrical length θ 1 is set to a value based on the above equation (1), and the 2 nd electrical length θ 2 is set to a value based on the above equation (2). This can increase the back-off amount.
Further, the 1 st output circuit 10 is constituted by the 1 st transmission line 11 and the 2 nd transmission line 12, the 2 nd output circuit 13 is constituted by the 3 rd transmission line 14, and the 2 nd transmission line 12 and the 3 rd transmission line 14 constitute a composite circuit, and the electrical length of the 1 st transmission line 11 is set to 90 degrees and the electrical length of the composite circuit is set to 90 degrees, whereby the electrical lengths of the output circuits 10, 13 are set to 180 degrees. This can increase the back-off amount. Further, the frequency characteristic compensation circuit 15 can be provided electrically in parallel with the 1 st output circuit 10.
The frequency characteristic compensation circuit 15 is formed of an open stub having an electrical length of 180 degrees. This enables the frequency characteristic compensation circuit 15 to be realized.
The term "90 degrees" recited in the claims of the present application is intended to include not only complete 90 degrees but also substantially 90 degrees. The term "180 degrees" recited in the claims of the present application is intended to include not only complete 180 degrees but also substantially 180 degrees.
Embodiment mode 2
Fig. 9 is a circuit diagram showing the main parts of the doherty amplifier of embodiment 2. A doherty amplifier of embodiment 2 will be described with reference to fig. 9. In fig. 9, the same components as those shown in fig. 1 are denoted by the same reference numerals, and description thereof is omitted.
As shown in fig. 9, the doherty amplifier 100a has a main amplifier 8a and an auxiliary amplifier 9 a. The input terminal 1, the input matching circuit 2, the divider 3, the 1 st input matching circuit 4, the phase correction circuit 5, the 2 nd input matching circuit 7, the main amplifier 8a, the auxiliary amplifier 9a, the 1 st output circuit 10, the 2 nd output circuit 13, the frequency characteristic compensation circuit 15, the output matching circuit 19, and the output terminal 20 constitute the main parts of the doherty amplifier 100 a.
In the amplifiers 8, 9 of the doherty amplifier 100, electrical characteristics (e.g., output resistance and output amplitude) of outputs with respect to the amount of bias are the same as each other. Therefore, assuming that the bias amounts of the amplifiers 8, 9 are set to the same values as each other, the electrical characteristics of the output of the main amplifier 8 are the same as the electrical characteristics of the output of the auxiliary amplifier 9. In this case, the saturated output power of the main amplifier 8 is the same as that of the auxiliary amplifier 9.
In contrast, in the amplifiers 8a and 9a of the doherty amplifier 100a, electrical characteristics of the output with respect to the bias amount are different from each other. Therefore, assuming that the bias amounts of the amplifiers 8a, 9a are set to the same value as each other, the electrical characteristics of the output of the main amplifier 8a and the electrical characteristics of the output of the auxiliary amplifier 9a are different. In this case, the saturated output power of the main amplifier 8a is different from the saturated output power of the auxiliary amplifier 9 a.
In the doherty amplifier 100, the optimum load impedance Ropt1 of the main amplifier 8 in the saturation operation state is the same as the optimum load impedance Ropt2 of the auxiliary amplifier 9 in the saturation operation state. For example, Ropt 1-Ropt and Ropt 2-Ropt. In contrast, in the doherty amplifier 100a, the optimum load impedance Ropt1 of the main amplifier 8a in the saturation operation state is different from the optimum load impedance Ropt2 of the auxiliary amplifier 9a in the saturation operation state. For example, with respect to Ropt1 ═ Ropt, Ropt2 ═ Ropt'.
In the doherty amplifier 100a, the characteristic impedance of the 1 st output circuit 10 is set to the same value as the optimum load impedance Ropt1 in the saturation operation state of the main amplifier 8 a. That is, the characteristic impedance is set to the same value as Ropt. In the doherty amplifier 100a, the characteristic impedance of the 2 nd output circuit 13 is set to the same value as the optimum load impedance Ropt2 in the saturation operation state of the auxiliary amplifier 9 a. That is, the characteristic impedance is set to the same value as Ropt'.
In the doherty amplifier 100a, the output matching circuit 19 obtains impedance matching between the output combining unit 18 and the output terminal 20 so that the impedance R on the output terminal 20 side becomes a value represented by the following formula (4).
R＝(Ropt×Ropt’)/(Ropt+Ropt’) (4)
As described above, in the doherty amplifier 100a, the saturated output power of the main amplifier 8a is different from that of the auxiliary amplifier 9 a. Even in such a case, the back-off can be increased and the bandwidth can be widened at the same time by the same operation as that of the doherty amplifier 100.
Fig. 10 is a circuit diagram showing the main parts of the doherty amplifier of embodiment 3. A doherty amplifier of embodiment 3 will be described with reference to fig. 10. In fig. 10, the same components as those shown in fig. 1 are denoted by the same reference numerals, and description thereof is omitted.
As shown in fig. 10, an output matching circuit (hereinafter, referred to as "1 st output matching circuit") 31 is provided between the main amplifier 8 and the 1 st output circuit 10. The 1 st output matching circuit 31 is composed of, for example, a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines. The electrical length of the 1 st output matching circuit 31 is set to a value corresponding to an integral multiple of 180 degrees or a value corresponding to an integral multiple of substantially 180 degrees when viewed from the output section of the main amplifier 8.
Further, an output matching circuit (hereinafter, referred to as "2 nd output matching circuit") 32 is provided between the auxiliary amplifier 9 and the 2 nd output circuit 13. The 2 nd output matching circuit 32 is constituted by, for example, a lumped constant circuit, a distributed constant circuit, a composite circuit based on a lumped constant and a distributed constant, an LC type matching circuit, or a circuit using 1 or more λ/4 lines. The electrical length of the 2 nd output matching circuit 32 is set to a value corresponding to an integral multiple of 180 degrees or a value corresponding to an integral multiple of substantially 180 degrees when viewed from the output portion of the auxiliary amplifier 9.
The input terminal 1, the input matching circuit 2, the distributor 3, the 1 st input matching circuit 4, the phase correction circuit 5, the 2 nd input matching circuit 7, the main amplifier 8, the auxiliary amplifier 9, the 1 st output circuit 10, the 2 nd output circuit 13, the frequency characteristic compensation circuit 15, the output matching circuit 19, the output terminal 20, the 1 st output matching circuit 31, and the 2 nd output matching circuit 32 constitute the main part of the doherty amplifier 100 b.
Since the 1 st output matching circuit 31 is provided, the optimum load impedance Ropt1 of the main amplifier 8 in the saturation operation state is converted into the optimum load impedance Ropt 1' of the amplifier (hereinafter referred to as "1 st amplifier") 33 configured by the main amplifier 8 and the 1 st output matching circuit 31. That is, the optimum load impedance Ropt 1' is a different value from the optimum load impedance Ropt 1. For example, with respect to Ropt1 ═ Ropt, Ropt1 ═ Ropt ".
Since the 2 nd output matching circuit 32 is provided, the optimum load impedance Ropt2 of the auxiliary amplifier 9 in the saturation operation state is converted into the optimum load impedance Ropt 2' of the amplifier (hereinafter, referred to as "2 nd amplifier") 34 configured by the auxiliary amplifier 9 and the 2 nd output matching circuit 32. That is, the optimum load impedance Ropt 2' is a different value from the optimum load impedance Ropt 2. For example, with respect to Ropt2 ═ Ropt, Ropt2 ═ Ropt ".
Therefore, the doherty amplifier 100b can be regarded as being provided with the 1 st amplifier 33 having the optimal load impedance Ropt 1' with respect to the doherty amplifier 100, instead of the main amplifier 8 having the optimal load impedance Ropt 1. Further, the doherty amplifier 100b can be regarded as being provided with the 2 nd amplifier 34 having the optimal load impedance Ropt 2' with respect to the doherty amplifier 100, instead of the auxiliary amplifier 9 having the optimal load impedance Ropt 2.
Thus, the operation of the doherty amplifier 100b can be regarded as the same as that of the doherty amplifier 100. By using the doherty amplifier 100b, it is possible to simultaneously increase the back-off and widen the band, as in the case of using the doherty amplifier 100.
In addition, the doherty amplifier 100b may have amplifiers 8a and 9a instead of the amplifiers 8 and 9.
The doherty amplifier 100b may have only one of the 1 st output matching circuit 31 and the 2 nd output matching circuit 32.
As described above, the doherty amplifier 100b has: a1 st output matching circuit 31 provided between the main amplifier 8 and the 1 st output circuit 10 and having an electrical length with respect to an integral multiple of 180 degrees; and a2 nd output matching circuit 32 which is provided between the auxiliary amplifier 9 and the 2 nd output circuit 13 and has an electrical length with respect to an integral multiple of 180 degrees. Even in such a case, the back-off can be increased and the bandwidth can be widened at the same time by the same operation as that of the doherty amplifier 100.
As described above, the meaning of the term "180 degrees" recited in the claims of the present application includes not only complete 180 degrees but also substantially 180 degrees.
Fig. 11 is a circuit diagram showing the main parts of the doherty amplifier of embodiment 4. A doherty amplifier of embodiment 4 will be described with reference to fig. 11. In fig. 11, the same components as those shown in fig. 1 are denoted by the same reference numerals, and description thereof is omitted.
As shown in fig. 11, a circuit (hereinafter, referred to as "1 st circuit") 41 is provided between the 1 st output circuit 10 and the output combining unit 18. The electrical length of the 1 st circuit 41 is set to a value corresponding to an integer multiple of 180 degrees or a value corresponding to an integer multiple of substantially 180 degrees. The 1 st circuit 41 is constituted by a transmission line 42, for example.
A circuit (hereinafter, referred to as "2 nd circuit") 43 is provided between the 2 nd output circuit 13 and the output combining unit 18. The electrical length of the 2 nd circuit 43 is set to a value corresponding to an integral multiple of 180 degrees or a value corresponding to an integral multiple of substantially 180 degrees. The 2 nd circuit 43 is constituted by a transmission line 44, for example.
The input terminal 1, the input matching circuit 2, the distributor 3, the 1 st input matching circuit 4, the phase correction circuit 5, the 2 nd input matching circuit 7, the main amplifier 8, the auxiliary amplifier 9, the 1 st output circuit 10, the 2 nd output circuit 13, the frequency characteristic compensation circuit 15, the output matching circuit 19, the output terminal 20, the 1 st circuit 41, and the 2 nd circuit 43 constitute the main parts of the doherty amplifier 100 c.
The operation of the doherty amplifier 100c is the same as that of the doherty amplifier 100. By using the doherty amplifier 100c, it is possible to simultaneously increase the back-off and widen the band, as in the case of using the doherty amplifier 100.
In addition, the doherty amplifier 100c may have amplifiers 8a and 9a instead of the amplifiers 8 and 9.
The doherty amplifier 100c may further include at least one of a1 st output matching circuit 31 and a2 nd output matching circuit 32.
The doherty amplifier 100c may have only one of the 1 st circuit 41 and the 2 nd circuit 43.
As described above, the doherty amplifier 100c has: a1 st circuit 41 provided between the 1 st output circuit 10 and the output combining section 18 and having an electrical length corresponding to an integral multiple of 180 degrees; and a2 nd circuit 43 which is provided between the 2 nd output circuit 13 and the output combining section 18 and has an electrical length with respect to an integral multiple of 180 degrees. Even in such a case, the back-off can be increased and the bandwidth can be widened at the same time by the same operation as that of the doherty amplifier 100.
As described above, the meaning of the term "180 degrees" recited in the claims of the present application includes not only complete 180 degrees but also substantially 180 degrees.
Fig. 12 is a circuit diagram showing the main parts of the doherty amplifier of embodiment 5. A doherty amplifier of embodiment 5 will be described with reference to fig. 12. In fig. 12, the same components as those shown in fig. 1 are denoted by the same reference numerals, and description thereof is omitted.
As shown in fig. 1, the doherty amplifier 100d has an input terminal (hereinafter, may be referred to as "1 st input terminal") 51 for the main amplifier 8. That is, the 1 st input matching circuit 4 is provided between the 1 st input terminal 51 and the main amplifier 8. The 1 st input terminal 51 receives a signal input to the 1 st path P1.
The doherty amplifier 100d has an input terminal 52 for the auxiliary amplifier 9 (hereinafter, may be referred to as "input terminal 2"). That is, the 2 nd input matching circuit 7 is provided between the 2 nd input terminal 52 and the auxiliary amplifier 9. The 2 nd input terminal 52 receives a signal input to the 2 nd path P2.
The 1 st input terminal 51 and the 2 nd input terminal 52 are electrically connected to a signal source 53, respectively. The signal source 53 is composed of, for example, an inverter, a DAC (Digital-to-Analog Converter) or a DDS (Direct Digital Synthesizer).
The main parts of the doherty amplifier 100d are constituted by the 1 st input matching circuit 4, the 2 nd input matching circuit 7, the main amplifier 8, the auxiliary amplifier 9, the 1 st output circuit 10, the 2 nd output circuit 13, the frequency characteristic compensating circuit 15, the output matching circuit 19, the output terminal 20, the 1 st input terminal 51, and the 2 nd input terminal 52.
In the doherty amplifier 100d, the gate bias of each of the main amplifier 8 and the auxiliary amplifier 9 is set to a value in the vicinity of a threshold for the gate bias. This causes the main amplifier 8 to be switched on/off according to the presence or absence of signal input to the 1 st input terminal 51. The auxiliary amplifier 9 is switched on/off according to the presence or absence of a signal input to the 2 nd input terminal 52.
Therefore, when the requested output power is equal to or higher than the predetermined value, the signal source 53 inputs a signal to the 1 st input terminal 51 and the 2 nd input terminal 52, respectively. Thereby, the main amplifier 8 is set to the on state, and the auxiliary amplifier 9 is set to the on state. On the other hand, when the requested output power is smaller than the predetermined value, the signal source 53 inputs a signal only to the 1 st input terminal 51. Thereby, the main amplifier 8 is set to the on state, and the auxiliary amplifier 9 is set to the off state.
That is, the doherty amplifier 100d can simultaneously realize the increase of the back-off amount and the widening of the bandwidth by the same operation as that of the doherty amplifier 100. In addition, by using the dedicated input terminals 51 and 52 for the amplifiers 8 and 9, the on/off of the amplifiers 8 and 9 can be appropriately controlled. As a result, the efficiency of the doherty amplifier 100d can be further improved. Further, a further improvement in the gain of the doherty amplifier 100d can be achieved.
In addition, the doherty amplifier 100d may also have a phase correction circuit 5. In this case, the phase correction circuit 5 may be provided between the 2 nd input terminal 52 and the 2 nd input matching circuit 7.
Further, the doherty amplifier 100d may also have amplifiers 8a, 9a instead of the amplifiers 8, 9.
The doherty amplifier 100d may further include at least one of the 1 st output matching circuit 31 and the 2 nd output matching circuit 32.
The doherty amplifier 100d may include at least one of the 1 st circuit 41 and the 2 nd circuit 43.
As described above, the doherty amplifier 100d has the 1 st input terminal 51 for the main amplifier 8 and the 2 nd input terminal 52 for the auxiliary amplifier 9, and the 1 st input terminal 51 and the 2 nd input terminal 52 are electrically connected to the signal source 53, respectively. This enables appropriate control of on/off of the amplifiers 8 and 9. As a result, the efficiency of the doherty amplifier 100d can be further improved. Further, a further improvement in the gain of the doherty amplifier 100d can be achieved.
In addition, in the present application, it is possible to freely combine the respective embodiments, to modify any of the components of the respective embodiments, and to omit any of the components of the respective embodiments within the scope of the invention.
Industrial applicability
The doherty amplifier of the invention can be used in, for example, a communication apparatus.
Description of the reference symbols
1: an input terminal; 2: an input matching circuit; 3: a dispenser; 4: a1 st input matching circuit; 5: a phase correction circuit; 6: a transmission line; 7: a2 nd input matching circuit; 8. 8 a: a main amplifier; 9. 9 a: an auxiliary amplifier; 10: a1 st output circuit; 11: 1 st transmission line; 12: a2 nd transmission line; 13: a2 nd output circuit; 14: a 3 rd transmission line; 15: a frequency characteristic compensation circuit; 16: an open stub; 17: a connecting portion; 18: an output combining unit; 19: an output matching circuit; 20: an output terminal; 21: a load; 31: a1 st output matching circuit; 32: a2 nd output matching circuit; 33: a1 st amplifier; 34: a2 nd amplifier; 41: a1 st circuit; 42: a transmission line; 43: a2 nd circuit; 44: a transmission line; 51: a1 st input terminal; 52: a2 nd input terminal; 53: a signal source; 100. 100a, 100b, 100c, 100 d: a doherty amplifier.
Claims (10)
1. A doherty amplifier, comprising:
an amplifier comprising a main amplifier and an auxiliary amplifier;
an output circuit for back-off amplification including a1 st output circuit having a1 st electrical length and provided between the main amplifier and an output combining section of the amplifier, and a2 nd output circuit having a2 nd electrical length and provided between the auxiliary amplifier and the output combining section; and
and a frequency characteristic compensation circuit for widening a band, which is provided electrically in parallel with the 1 st output circuit and compensates for a frequency characteristic of an impedance in the output circuit.
2. The Doherty amplifier of claim 1,
when the auxiliary amplifier is set to an off state, the 2 nd output circuit functions as an open stub, and thus the 2 nd output circuit functions as a capacitive load.
3. The Doherty amplifier of claim 1,
the capacitive impedance of the frequency characteristic compensation circuit cancels the inductive impedance of the output circuit in a high frequency domain with respect to a reference frequency, and the inductive impedance of the frequency characteristic compensation circuit cancels the capacitive impedance of the output circuit in a low frequency domain with respect to the reference frequency.
4. The Doherty amplifier of claim 1,
the 1 st electrical length theta 1 is set based on a numerical expression using a value gamma corresponding to a requested back-off amount
The value of (a) is,
the 2 nd electrical length θ 2 is set based on a numerical expression using a value γ corresponding to the requested back-off amount
The value of (c).
5. The Doherty amplifier of claim 1,
the 1 st output circuit is composed of a1 st transmission line and a2 nd transmission line,
the 2 nd output circuit is constituted by a 3 rd transmission line,
a synthesis circuit is formed by the 2 nd transmission line and the 3 rd transmission line,
the electrical length of the 1 st transmission line is set to 90 degrees, and the electrical length of the combining circuit is set to 90 degrees, whereby the electrical length of the output circuit is set to 180 degrees.
6. The Doherty amplifier of claim 1,
the frequency characteristic compensation circuit is constituted by an open stub having an electrical length of 180 degrees.
7. The Doherty amplifier of claim 1,
the saturated output power of the main amplifier is different from the saturated output power of the auxiliary amplifier.
8. A doherty amplifier as claimed in claim 1, wherein the doherty amplifier has:
a1 st output matching circuit provided between the main amplifier and the 1 st output circuit and having an electrical length with respect to an integral multiple of 180 degrees; and
a2 nd output matching circuit disposed between the auxiliary amplifier and the 2 nd output circuit and having an electrical length relative to an integer multiple of 180 degrees.
9. A doherty amplifier as claimed in claim 1, wherein the doherty amplifier has:
a1 st circuit provided between the 1 st output circuit and the output combining section, and having an electrical length corresponding to an integral multiple of 180 degrees; and
a2 nd circuit provided between the 2 nd output circuit and the output combining section, and having an electrical length corresponding to an integral multiple of 180 degrees.
10. The Doherty amplifier of claim 1,
the Doherty amplifier has a1 st input terminal for the main amplifier and a2 nd input terminal for the auxiliary amplifier,
the 1 st input terminal and the 2 nd input terminal are respectively electrically connected with a signal source.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2019/022751 WO2020246029A1 (en) | 2019-06-07 | 2019-06-07 | Doherty amplifier |
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| CN113906671A true CN113906671A (en) | 2022-01-07 |
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| CN201980097069.1A Pending CN113906671A (en) | 2019-06-07 | 2019-06-07 | Doherty amplifier |
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| US (1) | US20220069776A1 (en) |
| JP (1) | JP7003329B2 (en) |
| CN (1) | CN113906671A (en) |
| DE (1) | DE112019007283T5 (en) |
| WO (1) | WO2020246029A1 (en) |
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| KR20090043853A (en) * | 2007-10-30 | 2009-05-07 | 주식회사 웨이브일렉트로닉스 | Doherty amplifier |
| CN107425814A (en) * | 2017-08-07 | 2017-12-01 | 杭州电子科技大学 | A kind of broadband Doherty power amplifier based on compensation parasitic capacitance |
| CN108123686A (en) * | 2016-11-30 | 2018-06-05 | 住友电工光电子器件创新株式会社 | Doherty amplifier |
| US20190173435A1 (en) * | 2017-12-05 | 2019-06-06 | Nxp Usa, Inc. | Wideband power amplifiers with harmonic traps |
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| JP2007019578A (en) | 2005-07-05 | 2007-01-25 | Hitachi Ltd | Power amplifier and transmitter employing the same |
| US7649412B2 (en) | 2005-08-01 | 2010-01-19 | Mitsubishi Electric Corporation | High efficiency amplifier |
| KR100862056B1 (en) | 2007-08-06 | 2008-10-14 | (주) 와이팜 | Broadband power amplifier |
| KR20090071834A (en) * | 2007-12-28 | 2009-07-02 | 성균관대학교산학협력단 | Harmonic turned doherty amplifier |
| US10224882B2 (en) | 2017-01-13 | 2019-03-05 | Kabushiki Kaisha Toshiba | Harmonically tuned load modulated amplifier |
| JP6214843B1 (en) | 2017-01-24 | 2017-10-18 | 三菱電機株式会社 | Doherty amplifier |
| WO2019097609A1 (en) | 2017-11-15 | 2019-05-23 | 三菱電機株式会社 | Doherty amplifier and doherty amplifier circuit |
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2019
- 2019-06-07 DE DE112019007283.8T patent/DE112019007283T5/en active Pending
- 2019-06-07 CN CN201980097069.1A patent/CN113906671A/en active Pending
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| KR20090043853A (en) * | 2007-10-30 | 2009-05-07 | 주식회사 웨이브일렉트로닉스 | Doherty amplifier |
| CN108123686A (en) * | 2016-11-30 | 2018-06-05 | 住友电工光电子器件创新株式会社 | Doherty amplifier |
| CN107425814A (en) * | 2017-08-07 | 2017-12-01 | 杭州电子科技大学 | A kind of broadband Doherty power amplifier based on compensation parasitic capacitance |
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| JP7003329B2 (en) | 2022-01-20 |
| JPWO2020246029A1 (en) | 2021-09-30 |
| DE112019007283T5 (en) | 2022-02-03 |
| US20220069776A1 (en) | 2022-03-03 |
| WO2020246029A1 (en) | 2020-12-10 |
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